textproduct: Quad Cities

KEY MESSAGES

- An area of showers and a few embedded storms will continue to lift northeastward this afternoon and early evening.

- We continue to have multiple days of severe weather risks this week, especially for Tuesday and Wednesday, with more uncertainty for Monday's severe potential.

- Warm and seasonably humid conditions are expected for Monday through Wednesday this week.

SHORT TERM /THROUGH MONDAY/

Issued at 227 PM CDT Sun Apr 12 2026

An active afternoon continues over most of the area, thanks to a low- amplitude shortwave trough lifting northeastward. A strong south- southwesterly low-level jet will also accompany the shortwave, helping to increase theta-e advection and supporting some wetting rainfall across the area. Limited instability should severe potential low, with the 12.12z HREF ensemble SBCAPE values around 500 J/kg. With the stout LLJ in place, can't rule out some locally strong winds that could be generated by stronger storms (gusting up to 50 mph), but otherwise, we're not outlooked for any severe weather by SPC. In total, rainfall amounts should generally range between one-quarter to a half- inch for most locations today, with the higher amounts now more likely along a line from Sigourney, IA northeast towards Freeport, IL (a shift to the northwest from the previous forecast).

Once the evening showers/storms come to an end, the remainder of tonight looks to remain quiet under mostly cloudy skies, possibly some fog to develop along the Highway 20 corridor. Low temperatures will remain mild for this time of the year, with lows in the upper 50s to lower 60s.

We continue to eye the potential for strong to severe storms for Monday, although confidence continues to remain low. Models continue to prog a developing surface low over the WY/SD/NE border via lee cyclogenesis ahead of an approaching longwave upper trough. The general consensus of the guidance indicates a warm frontal zone to lift northward over Minnesota and Wisconsin as the surface low approaches. This places us well within the warm sector, with temperatures increasing even further, into the middle to upper 70s for highs. As far as severe weather potential is concerned, there are a few scenarios that could play out:

1) storms initiate along the warm front to the north, and with the instability gradient more oriented west to east and the nose of the LLJ aimed north of our region, severe convection would develop along the boundary and remain to the north, or

2) storms initiate along a trailing cold front over western Iowa and translate eastward towards our area. These appear possible to consolidate and generate a strong wind threat, mainly along our north.

Of these two scenarios, scenario 1 appears to be more likely, given a pretty stout elevated mixed layer (EML) and capping inversion in place. While our atmosphere will be quite unstable, these factors could help limit our severe weather potential. However, with the possibility that scenario 2 occurs, SPC has maintained our Slight Risk (level 2 of 5) along the Highway 20 corridor, with a Marginal Risk (level 1 of 5) as far south of Interstate 80.

LONG TERM /MONDAY NIGHT THROUGH SUNDAY/

Issued at 230 PM CDT Sun Apr 12 2026

Our attention for the long-term period starts right off the bat with another severe storm risk for Tuesday, and this one appears to be more likely to be active for us. The aforementioned warm front from Monday appears to be pulled southward by yet another surface low, this one developing over the central Plains (farther south than the Monday low pressure system). There remain some uncertainty on the influence of previous convection (if any develop) on how things evolve on Tuesday. If the boundary does reach our northwestern CWA by Tuesday afternoon/evening, it will be game on for strong/severe storms, especially considering the volatile thermodynamic and kinematic environment. As high temperatures warm into lower 80s for most, expect instability to be quite high, with the GEFS ensemble probability of SBCAPE of 2000 J/kg or higher around 50-80+ percent across our southeastern 2/3rds of the CWA. Currently, SPC has maintained a widespread Slight Risk for our area, with all severe hazards possible, including large hail, damaging winds, and tornadoes. There is also a possibility for a higher threat level to be introduced for subsequent outlooks. Stay tuned for updates about Tuesday!

For Wednesday through Friday, the active pattern will only continue as the primary upper-level longwave trough finally moves through the area Wednesday, followed by yet another one on Friday. We continue to be outlooked by SPC for Slight Risks both days in our region. Much uncertainty remains on the timing and severity as prior convection can augment the environment, but the various machine learning severe probability tools suggest these days to be volatile from an environmental perspective, so more to keep an eye on as we approach these portions of the week. Prepare for a busy severe weather week!

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/

Issued at 632 PM CDT Sun Apr 12 2026

Scattered showers with occasional IFR vsbys will continue to move through eastern IA and northwest IL over the next 2-3 hours ending from west to east. Gusty southwest winds will accompany these showers and then will decrease under 12kts late evening. Model guidance is quite pessimistic on LIFR/IFR clouds developing late tonight especially at CID/DBQ, but I am not overly confident on the duration of LIFR conditions. Kept IFR cigs out of BRL/MLI for now until confidence increases. There is also a possibility of MVFR/IFR fog developing prior to sunrise at CID/DBQ and have included this given the wet ground. Otherwise, MVFR/IFR conditions will persist through the morning/early afternoon on Monday due to a trapping inversion before conditions gradually return to VFR. South winds will also increase late in the period with occasional gusts over 25 kts.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.